Novel organic activators for single site iron catalysts
Résumé
The synthesis of new organo-aluminum derivatives based on the reaction of carboxylic acids with trialkylaluminum and their use as co-catalysts for ethylene polymerization, in the presence of iron catalyst is described. These co-catalysts were obtained through the reaction of acetic acid, benzoic acid, or benzoic acid derivatives with different trialkylaluminums. The most promising co-catalyst was obtained from the reaction of benzene tricarboxylic acid (BTCA) with trimethylaluminum (TMA). The influence of alkylaluminum/BTCA ratio, reaction time, and temperature on the ethylene polymerization activity was investigated. H-1 NMR spectra of some of the most active co-catalysts confirm the formation of alumoxane-type species. Polymerization activities of the same order or even higher to those found using "pure" trialkylaluminums or methylaluminoxane (MAO) co-catalysts were obtained.